15 files changed, 260 insertions, 49 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0e8457da6f95..600c1629b64d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -185,6 +185,9 @@ static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
 static void update_context_time(struct perf_event_context *ctx);
 static u64 perf_event_time(struct perf_event *event);
 
+static void ring_buffer_attach(struct perf_event *event,
+                               struct ring_buffer *rb);
+
 void __weak perf_event_print_debug(void)        { }
 
 extern __weak const char *perf_pmu_name(void)
@@ -2173,7 +2176,8 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx,
 
         perf_event_sched_in(cpuctx, ctx, task);
 
-        cpuctx->task_ctx = ctx;
+        if (ctx->nr_events)
+                cpuctx->task_ctx = ctx;
 
         perf_pmu_enable(ctx->pmu);
         perf_ctx_unlock(cpuctx, ctx);
@@ -3190,12 +3194,33 @@ static unsigned int perf_poll(struct file *file, poll_table *wait)
         struct ring_buffer *rb;
         unsigned int events = POLL_HUP;
 
+        /*
+         * Race between perf_event_set_output() and perf_poll(): perf_poll()
+         * grabs the rb reference but perf_event_set_output() overrides it.
+         * Here is the timeline for two threads T1, T2:
+         * t0: T1, rb = rcu_dereference(event->rb)
+         * t1: T2, old_rb = event->rb
+         * t2: T2, event->rb = new rb
+         * t3: T2, ring_buffer_detach(old_rb)
+         * t4: T1, ring_buffer_attach(rb1)
+         * t5: T1, poll_wait(event->waitq)
+         *
+         * To avoid this problem, we grab mmap_mutex in perf_poll()
+         * thereby ensuring that the assignment of the new ring buffer
+         * and the detachment of the old buffer appear atomic to perf_poll()
+         */
+        mutex_lock(&event->mmap_mutex);
+
         rcu_read_lock();
         rb = rcu_dereference(event->rb);
-        if (rb)
+        if (rb) {
+                ring_buffer_attach(event, rb);
                 events = atomic_xchg(&rb->poll, 0);
+        }
         rcu_read_unlock();
 
+        mutex_unlock(&event->mmap_mutex);
+
         poll_wait(file, &event->waitq, wait);
 
         return events;
@@ -3496,6 +3521,49 @@ unlock:
         return ret;
 }
 
+static void ring_buffer_attach(struct perf_event *event,
+                               struct ring_buffer *rb)
+{
+        unsigned long flags;
+
+        if (!list_empty(&event->rb_entry))
+                return;
+
+        spin_lock_irqsave(&rb->event_lock, flags);
+        if (!list_empty(&event->rb_entry))
+                goto unlock;
+
+        list_add(&event->rb_entry, &rb->event_list);
+unlock:
+        spin_unlock_irqrestore(&rb->event_lock, flags);
+}
+
+static void ring_buffer_detach(struct perf_event *event,
+                               struct ring_buffer *rb)
+{
+        unsigned long flags;
+
+        if (list_empty(&event->rb_entry))
+                return;
+
+        spin_lock_irqsave(&rb->event_lock, flags);
+        list_del_init(&event->rb_entry);
+        wake_up_all(&event->waitq);
+        spin_unlock_irqrestore(&rb->event_lock, flags);
+}
+
+static void ring_buffer_wakeup(struct perf_event *event)
+{
+        struct ring_buffer *rb;
+
+        rcu_read_lock();
+        rb = rcu_dereference(event->rb);
+        list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
+                wake_up_all(&event->waitq);
+        }
+        rcu_read_unlock();
+}
+
 static void rb_free_rcu(struct rcu_head *rcu_head)
 {
         struct ring_buffer *rb;
@@ -3521,9 +3589,19 @@ static struct ring_buffer *ring_buffer_get(struct perf_event *event)
 
 static void ring_buffer_put(struct ring_buffer *rb)
 {
+        struct perf_event *event, *n;
+        unsigned long flags;
+
         if (!atomic_dec_and_test(&rb->refcount))
                 return;
 
+        spin_lock_irqsave(&rb->event_lock, flags);
+        list_for_each_entry_safe(event, n, &rb->event_list, rb_entry) {
+                list_del_init(&event->rb_entry);
+                wake_up_all(&event->waitq);
+        }
+        spin_unlock_irqrestore(&rb->event_lock, flags);
+
         call_rcu(&rb->rcu_head, rb_free_rcu);
 }
 
@@ -3546,6 +3624,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
                 atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm);
                 vma->vm_mm->pinned_vm -= event->mmap_locked;
                 rcu_assign_pointer(event->rb, NULL);
+                ring_buffer_detach(event, rb);
                 mutex_unlock(&event->mmap_mutex);
 
                 ring_buffer_put(rb);
@@ -3700,7 +3779,7 @@ static const struct file_operations perf_fops = {
 
 void perf_event_wakeup(struct perf_event *event)
 {
-        wake_up_all(&event->waitq);
+        ring_buffer_wakeup(event);
 
         if (event->pending_kill) {
                 kill_fasync(&event->fasync, SIGIO, event->pending_kill);
@@ -5822,6 +5901,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
         INIT_LIST_HEAD(&event->group_entry);
         INIT_LIST_HEAD(&event->event_entry);
         INIT_LIST_HEAD(&event->sibling_list);
+        INIT_LIST_HEAD(&event->rb_entry);
+
         init_waitqueue_head(&event->waitq);
         init_irq_work(&event->pending, perf_pending_event);
 
@@ -6028,6 +6109,8 @@ set:
 
         old_rb = event->rb;
         rcu_assign_pointer(event->rb, rb);
+        if (old_rb)
+                ring_buffer_detach(event, old_rb);
         ret = 0;
 unlock:
         mutex_unlock(&event->mmap_mutex);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 09097dd8116c..64568a699375 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -22,6 +22,9 @@ struct ring_buffer {
         local_t                         lost;           /* nr records lost   */
 
         long                            watermark;      /* wakeup watermark  */
+        /* poll crap */
+        spinlock_t                      event_lock;
+        struct list_head                event_list;
 
         struct perf_event_mmap_page     *user_page;
         void                            *data_pages[0];
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index a2a29205cc0f..7f3011c6b57f 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -209,6 +209,9 @@ ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
                 rb->writable = 1;
 
         atomic_set(&rb->refcount, 1);
+
+        INIT_LIST_HEAD(&rb->event_list);
+        spin_lock_init(&rb->event_lock);
 }
 
 #ifndef CONFIG_PERF_USE_VMALLOC
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0e2b179bc7b3..1da999f5e746 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -623,8 +623,9 @@ static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
 
 static int irq_wait_for_interrupt(struct irqaction *action)
 {
+        set_current_state(TASK_INTERRUPTIBLE);
+
         while (!kthread_should_stop()) {
-                set_current_state(TASK_INTERRUPTIBLE);
 
                 if (test_and_clear_bit(IRQTF_RUNTHREAD,
                                        &action->thread_flags)) {
@@ -632,7 +633,9 @@ static int irq_wait_for_interrupt(struct irqaction *action)
                         return 0;
                 }
                 schedule();
+                set_current_state(TASK_INTERRUPTIBLE);
         }
+        __set_current_state(TASK_RUNNING);
         return -1;
 }
 
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index bbdfe2a462a0..66ff7109f697 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -66,8 +66,9 @@ void jump_label_inc(struct jump_label_key *key)
                 return;
 
         jump_label_lock();
-        if (atomic_add_return(1, &key->enabled) == 1)
+        if (atomic_read(&key->enabled) == 0)
                 jump_label_update(key, JUMP_LABEL_ENABLE);
+        atomic_inc(&key->enabled);
         jump_label_unlock();
 }
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 0e9344a71be3..d6b149ccf925 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -71,6 +71,7 @@
 #include <linux/ctype.h>
 #include <linux/ftrace.h>
 #include <linux/slab.h>
+#include <linux/init_task.h>
 
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>
@@ -4810,6 +4811,9 @@ EXPORT_SYMBOL(wait_for_completion);
  * This waits for either a completion of a specific task to be signaled or for a
  * specified timeout to expire. The timeout is in jiffies. It is not
  * interruptible.
+ *
+ * The return value is 0 if timed out, and positive (at least 1, or number of
+ * jiffies left till timeout) if completed.
  */
 unsigned long __sched
 wait_for_completion_timeout(struct completion *x, unsigned long timeout)
@@ -4824,6 +4828,8 @@ EXPORT_SYMBOL(wait_for_completion_timeout);
  *
  * This waits for completion of a specific task to be signaled. It is
  * interruptible.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if completed.
  */
 int __sched wait_for_completion_interruptible(struct completion *x)
 {
@@ -4841,6 +4847,9 @@ EXPORT_SYMBOL(wait_for_completion_interruptible);
  *
  * This waits for either a completion of a specific task to be signaled or for a
  * specified timeout to expire. It is interruptible. The timeout is in jiffies.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
+ * positive (at least 1, or number of jiffies left till timeout) if completed.
  */
 long __sched
 wait_for_completion_interruptible_timeout(struct completion *x,
@@ -4856,6 +4865,8 @@ EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
  *
  * This waits to be signaled for completion of a specific task. It can be
  * interrupted by a kill signal.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if completed.
  */
 int __sched wait_for_completion_killable(struct completion *x)
 {
@@ -4874,6 +4885,9 @@ EXPORT_SYMBOL(wait_for_completion_killable);
  * This waits for either a completion of a specific task to be
  * signaled or for a specified timeout to expire. It can be
  * interrupted by a kill signal. The timeout is in jiffies.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
+ * positive (at least 1, or number of jiffies left till timeout) if completed.
  */
 long __sched
 wait_for_completion_killable_timeout(struct completion *x,
@@ -6099,6 +6113,9 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
          */
         idle->sched_class = &idle_sched_class;
         ftrace_graph_init_idle_task(idle, cpu);
+#if defined(CONFIG_SMP)
+        sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
+#endif
 }
 
 /*
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5c9e67923b7c..a78ed2736ba7 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -772,19 +772,32 @@ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
                 list_del_leaf_cfs_rq(cfs_rq);
 }
 
+static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
+{
+        long tg_weight;
+
+        /*
+         * Use this CPU's actual weight instead of the last load_contribution
+         * to gain a more accurate current total weight. See
+         * update_cfs_rq_load_contribution().
+         */
+        tg_weight = atomic_read(&tg->load_weight);
+        tg_weight -= cfs_rq->load_contribution;
+        tg_weight += cfs_rq->load.weight;
+
+        return tg_weight;
+}
+
 static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
 {
-        long load_weight, load, shares;
+        long tg_weight, load, shares;
 
+        tg_weight = calc_tg_weight(tg, cfs_rq);
         load = cfs_rq->load.weight;
 
-        load_weight = atomic_read(&tg->load_weight);
-        load_weight += load;
-        load_weight -= cfs_rq->load_contribution;
-
         shares = (tg->shares * load);
-        if (load_weight)
-                shares /= load_weight;
+        if (tg_weight)
+                shares /= tg_weight;
 
         if (shares < MIN_SHARES)
                 shares = MIN_SHARES;
@@ -1743,7 +1756,7 @@ static void __return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 
 static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 {
-        if (!cfs_rq->runtime_enabled || !cfs_rq->nr_running)
+        if (!cfs_rq->runtime_enabled || cfs_rq->nr_running)
                 return;
 
         __return_cfs_rq_runtime(cfs_rq);
@@ -2036,36 +2049,100 @@ static void task_waking_fair(struct task_struct *p)
  * Adding load to a group doesn't make a group heavier, but can cause movement
  * of group shares between cpus. Assuming the shares were perfectly aligned one
  * can calculate the shift in shares.
+ *
+ * Calculate the effective load difference if @wl is added (subtracted) to @tg
+ * on this @cpu and results in a total addition (subtraction) of @wg to the
+ * total group weight.
+ *
+ * Given a runqueue weight distribution (rw_i) we can compute a shares
+ * distribution (s_i) using:
+ *
+ *   s_i = rw_i / \Sum rw_j                                             (1)
+ *
+ * Suppose we have 4 CPUs and our @tg is a direct child of the root group and
+ * has 7 equal weight tasks, distributed as below (rw_i), with the resulting
+ * shares distribution (s_i):
+ *
+ *   rw_i = {   2,   4,   1,   0 }
+ *   s_i  = { 2/7, 4/7, 1/7,   0 }
+ *
+ * As per wake_affine() we're interested in the load of two CPUs (the CPU the
+ * task used to run on and the CPU the waker is running on), we need to
+ * compute the effect of waking a task on either CPU and, in case of a sync
+ * wakeup, compute the effect of the current task going to sleep.
+ *
+ * So for a change of @wl to the local @cpu with an overall group weight change
+ * of @wl we can compute the new shares distribution (s'_i) using:
+ *
+ *   s'_i = (rw_i + @wl) / (@wg + \Sum rw_j)                            (2)
+ *
+ * Suppose we're interested in CPUs 0 and 1, and want to compute the load
+ * differences in waking a task to CPU 0. The additional task changes the
+ * weight and shares distributions like:
+ *
+ *   rw'_i = {   3,   4,   1,   0 }
+ *   s'_i  = { 3/8, 4/8, 1/8,   0 }
+ *
+ * We can then compute the difference in effective weight by using:
+ *
+ *   dw_i = S * (s'_i - s_i)                                            (3)
+ *
+ * Where 'S' is the group weight as seen by its parent.
+ *
+ * Therefore the effective change in loads on CPU 0 would be 5/56 (3/8 - 2/7)
+ * times the weight of the group. The effect on CPU 1 would be -4/56 (4/8 -
+ * 4/7) times the weight of the group.
  */
 static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
 {
         struct sched_entity *se = tg->se[cpu];
 
-        if (!tg->parent)
+        if (!tg->parent)        /* the trivial, non-cgroup case */
                 return wl;
 
         for_each_sched_entity(se) {
-                long lw, w;
+                long w, W;
 
                 tg = se->my_q->tg;
-                w = se->my_q->load.weight;
 
-                /* use this cpu's instantaneous contribution */
-                lw = atomic_read(&tg->load_weight);
-                lw -= se->my_q->load_contribution;
-                lw += w + wg;
+                /*
+                 * W = @wg + \Sum rw_j
+                 */
+                W = wg + calc_tg_weight(tg, se->my_q);
 
-                wl += w;
+                /*
+                 * w = rw_i + @wl
+                 */
+                w = se->my_q->load.weight + wl;
 
-                if (lw > 0 && wl < lw)
-                        wl = (wl * tg->shares) / lw;
+                /*
+                 * wl = S * s'_i; see (2)
+                 */
+                if (W > 0 && w < W)
+                        wl = (w * tg->shares) / W;
                 else
                         wl = tg->shares;
 
-                /* zero point is MIN_SHARES */
+                /*
+                 * Per the above, wl is the new se->load.weight value; since
+                 * those are clipped to [MIN_SHARES, ...) do so now. See
+                 * calc_cfs_shares().
+                 */
                 if (wl < MIN_SHARES)
                         wl = MIN_SHARES;
+
+                /*
+                 * wl = dw_i = S * (s'_i - s_i); see (3)
+                 */
                 wl -= se->load.weight;
+
+                /*
+                 * Recursively apply this logic to all parent groups to compute
+                 * the final effective load change on the root group. Since
+                 * only the @tg group gets extra weight, all parent groups can
+                 * only redistribute existing shares. @wl is the shift in shares
+                 * resulting from this level per the above.
+                 */
                 wg = 0;
         }
 
@@ -2249,7 +2326,8 @@ static int select_idle_sibling(struct task_struct *p, int target)
         int cpu = smp_processor_id();
         int prev_cpu = task_cpu(p);
         struct sched_domain *sd;
-        int i;
+        struct sched_group *sg;
+        int i, smt = 0;
 
         /*
          * If the task is going to be woken-up on this cpu and if it is
@@ -2269,25 +2347,38 @@ static int select_idle_sibling(struct task_struct *p, int target)
          * Otherwise, iterate the domains and find an elegible idle cpu.
          */
         rcu_read_lock();
+again:
         for_each_domain(target, sd) {
-                if (!(sd->flags & SD_SHARE_PKG_RESOURCES))
-                        break;
+                if (!smt && (sd->flags & SD_SHARE_CPUPOWER))
+                        continue;
 
-                for_each_cpu_and(i, sched_domain_span(sd), tsk_cpus_allowed(p)) {
-                        if (idle_cpu(i)) {
-                                target = i;
-                                break;
+                if (!(sd->flags & SD_SHARE_PKG_RESOURCES)) {
+                        if (!smt) {
+                                smt = 1;
+                                goto again;
                         }
+                        break;
                 }
 
-                /*
-                 * Lets stop looking for an idle sibling when we reached
-                 * the domain that spans the current cpu and prev_cpu.
-                 */
-                if (cpumask_test_cpu(cpu, sched_domain_span(sd)) &&
-                    cpumask_test_cpu(prev_cpu, sched_domain_span(sd)))
-                        break;
+                sg = sd->groups;
+                do {
+                        if (!cpumask_intersects(sched_group_cpus(sg),
+                                                tsk_cpus_allowed(p)))
+                                goto next;
+
+                        for_each_cpu(i, sched_group_cpus(sg)) {
+                                if (!idle_cpu(i))
+                                        goto next;
+                        }
+
+                        target = cpumask_first_and(sched_group_cpus(sg),
+                                        tsk_cpus_allowed(p));
+                        goto done;
+next:
+                        sg = sg->next;
+                } while (sg != sd->groups);
         }
+done:
         rcu_read_unlock();
 
         return target;
@@ -3511,7 +3602,7 @@ static bool update_sd_pick_busiest(struct sched_domain *sd,
 }
 
 /**
- * update_sd_lb_stats - Update sched_group's statistics for load balancing.
+ * update_sd_lb_stats - Update sched_domain's statistics for load balancing.
  * @sd: sched_domain whose statistics are to be updated.
  * @this_cpu: Cpu for which load balance is currently performed.
  * @idle: Idle status of this_cpu
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index efa0a7b75dde..84802245abd2 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -67,3 +67,4 @@ SCHED_FEAT(NONTASK_POWER, 1)
 SCHED_FEAT(TTWU_QUEUE, 1)
 
 SCHED_FEAT(FORCE_SD_OVERLAP, 0)
+SCHED_FEAT(RT_RUNTIME_SHARE, 1)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 056cbd2e2a27..583a1368afe6 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -560,6 +560,9 @@ static int balance_runtime(struct rt_rq *rt_rq)
 {
         int more = 0;
 
+        if (!sched_feat(RT_RUNTIME_SHARE))
+                return more;
+
         if (rt_rq->rt_time > rt_rq->rt_runtime) {
                 raw_spin_unlock(&rt_rq->rt_runtime_lock);
                 more = do_balance_runtime(rt_rq);
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 1ecd6ba36d6c..c4eb71c8b2ea 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -387,6 +387,7 @@ void clockevents_exchange_device(struct clock_event_device *old,
          * released list and do a notify add later.
          */
         if (old) {
+                old->event_handler = clockevents_handle_noop;
                 clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
                 list_del(&old->list);
                 list_add(&old->list, &clockevents_released);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index cfc65e1eb9fb..da2f760e780c 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -548,7 +548,7 @@ static u64 clocksource_max_deferment(struct clocksource *cs)
          * note a margin of 12.5% is used because this can be computed with
          * a shift, versus say 10% which would require division.
          */
-        return max_nsecs - (max_nsecs >> 5);
+        return max_nsecs - (max_nsecs >> 3);
 }
 
 #ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
@@ -669,7 +669,7 @@ void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq)
          * ~ 0.06ppm granularity for NTP. We apply the same 12.5%
          * margin as we do in clocksource_max_deferment()
          */
-        sec = (cs->mask - (cs->mask >> 5));
+        sec = (cs->mask - (cs->mask >> 3));
         do_div(sec, freq);
         do_div(sec, scale);
         if (!sec)
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f954282d9a82..fd4a7b1625a2 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -71,7 +71,7 @@ int tick_check_broadcast_device(struct clock_event_device *dev)
              (dev->features & CLOCK_EVT_FEAT_C3STOP))
                 return 0;
 
-        clockevents_exchange_device(NULL, dev);
+        clockevents_exchange_device(tick_broadcast_device.evtdev, dev);
         tick_broadcast_device.evtdev = dev;
         if (!cpumask_empty(tick_get_broadcast_mask()))
                 tick_broadcast_start_periodic(dev);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 900b409543db..b1e8943fed1d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -152,7 +152,6 @@ void clear_ftrace_function(void)
         ftrace_pid_function = ftrace_stub;
 }
 
-#undef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 /*
  * For those archs that do not test ftrace_trace_stop in their
@@ -1212,7 +1211,9 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
         if (!src->count) {
                 free_ftrace_hash_rcu(*dst);
                 rcu_assign_pointer(*dst, EMPTY_HASH);
-                return 0;
+                /* still need to update the function records */
+                ret = 0;
+                goto out;
         }
 
         /*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 581876f9f387..c212a7f934ec 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1078,7 +1078,6 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
         /* First see if we did not already create this dir */
         list_for_each_entry(system, &event_subsystems, list) {
                 if (strcmp(system->name, name) == 0) {
-                        __get_system(system);
                         system->nr_events++;
                         return system->entry;
                 }
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 816d3d074979..95dc31efd6dd 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1649,7 +1649,9 @@ static int replace_system_preds(struct event_subsystem *system,
                  */
                 err = replace_preds(call, NULL, ps, filter_string, true);
                 if (err)
-                        goto fail;
+                        call->flags |= TRACE_EVENT_FL_NO_SET_FILTER;
+                else
+                        call->flags &= ~TRACE_EVENT_FL_NO_SET_FILTER;
         }
 
         list_for_each_entry(call, &ftrace_events, list) {
@@ -1658,6 +1660,9 @@ static int replace_system_preds(struct event_subsystem *system,
                 if (strcmp(call->class->system, system->name) != 0)
                         continue;
 
+                if (call->flags & TRACE_EVENT_FL_NO_SET_FILTER)
+                        continue;
+
                 filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
                 if (!filter_item)
                         goto fail_mem;
@@ -1686,7 +1691,7 @@ static int replace_system_preds(struct event_subsystem *system,
                  * replace the filter for the call.
                  */
                 filter = call->filter;
-                call->filter = filter_item->filter;
+                rcu_assign_pointer(call->filter, filter_item->filter);
                 filter_item->filter = filter;
 
                 fail = false;
@@ -1741,7 +1746,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
                 filter = call->filter;
                 if (!filter)
                         goto out_unlock;
-                call->filter = NULL;
+                RCU_INIT_POINTER(call->filter, NULL);
                 /* Make sure the filter is not being used */
                 synchronize_sched();
                 __free_filter(filter);
@@ -1782,7 +1787,7 @@ out:
          * string
          */
         tmp = call->filter;
-        call->filter = filter;
+        rcu_assign_pointer(call->filter, filter);
         if (tmp) {
                 /* Make sure the call is done with the filter */
                 synchronize_sched();